NEWCASTLE, England, April 14 (UPI) — British researchers say they have transferred DNA from one fertilized human egg to another egg that may allow some with rare genetic disorders to have children.

Researchers at Newcastle University in England said the procedure prevents damaged mitochondrial DNA — which can cause serious conditions such as muscular weakness, blindness and heart failure — from being passed on by the mother, the BBC reported Wednesday.

Lead author Doug Turnbull says the technique, done during in vitro fertilization, removes nuclei from the father’s sperm and the mother’s egg, leaves behind the faulty mitochondria and transfers the embryo to a donor egg, the researchers said.

The donor egg has had its nucleus removed, but it retains its mitochondria.

Dr. Donald Bruce, former director of the Society, Religion and Technology Project of the Church of Scotland, who is an expert on ethics, said the procedure — still several years in the future — raises ethical questions such as the safety of children with DNA from two mothers and genetic changes made to unborn children.